Akeyincryptographyis defined as a piece of information that determines the functional output of analgorithmorcipher. In the process ofEncryption, a key specifies the conversion of aplaintextinto cipher textand cipher text into a plaintext duringdecryption. Akeyis a piece of variable data that is fed as input into a cryptographic algorithm to perform one such operation. Keys are widely used in other cryptographic algorithms, such asdigital signatureschemes and message authentication codes. Without the usage of keys, a specific algorithm would produce no valid result.